Patent Document 1 discloses a semiconductor device including a vertical semiconductor element having a super-junction (SJ) structure in which N-type columns and P-type columns are alternately and repeatedly formed in a striped shape in a drift layer. With the SJ structure, an electric current path in which an electric current easily flows is formed, resulting in a lower ON resistance. Also, with the SJ structure, the concentration of an electric field is avoided so that a high breakdown voltage is obtained. In other words, both of the high breakdown voltage and the low ON resistance are achieved.
The semiconductor device is provided with a structure in which, in a cell region where the vertical semiconductor element is formed, a charge balance is maintained such that the P-type columns and the N-type columns have equal impurity concentrations while, in a peripheral region surrounding the cell region, a difference is provided between the respective impurity concentrations of the P-type columns and the N-type columns. Specifically, with regard to the difference between the impurity amount in each of the P-type columns and the impurity amount in each of the N-type columns, the difference between the impurity amounts in the combination of the P-type column and the N-type column located on the outermost periphery of the peripheral region is adjusted to be smaller than the difference between the impurity amounts in another combination of the P-type column and the N-type column located in the peripheral region, while the difference between the impurity amounts in the combination of the P-type column and the N-type column located on the innermost periphery of the peripheral region is adjusted to be larger than the difference between the impurity amounts in a combination of the P-type column and the N-type column located in the cell region.